
The Sahara Sea was the name of a hypothetical
macro-engineering
In engineering, macro-engineering (alternatively known as mega engineering) is the implementation of large-scale design projects. It can be seen as a branch of civil engineering or structural engineering applied on a large landmass. In particular ...
project which proposed flooding
endorheic basin
An endorheic basin ( ; also endoreic basin and endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water (e.g. rivers and oceans); instead, the water drainage flows into permanent ...
s in the
Sahara
The Sahara (, ) is a desert spanning across North Africa. With an area of , it is the largest hot desert in the world and the list of deserts by area, third-largest desert overall, smaller only than the deserts of Antarctica and the northern Ar ...
with waters from the
Atlantic Ocean
The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...
or
Mediterranean Sea
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...
. The goal of this unrealised project was to create an
inland sea that would cover the substantial areas of the Sahara which lie below
sea level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
, bringing humid air, rain, and agriculture deep into the desert.
The possibility of such a project was raised several times by different scientists and engineers during the late 19th century and early 20th century. The concept of a flooded Sahara was also featured in novels of the time.
History
19th century
In 1877 the Scottish entrepreneur and abolitionist
Donald Mackenzie was the first to propose the creation of a Sahara Sea. Mackenzie's idea was to cut a channel from one of the sand-barred lagoons north of
Cape Juby
Cape Juby (, trans. ''Raʾs Juby'', ) is a cape on the coast of southern Morocco, near the border with Western Sahara, directly east of the Canary Islands.
Its surrounding area, including the cities of Tarfaya and Tan-Tan, is called the C ...
, south to a large plain which Arab traders had identified to him as
El Djouf.
Mackenzie believed this vast region was up to below sea level and that flooding it would create an inland sea of suited to commercial navigation and even agriculture. He further believed that geological evidence suggested this basin had once been connected to the Atlantic via a channel near the
Saguia el-Hamra. He proposed that this inland sea, if augmented with a canal, could provide access to the
Niger River
The Niger River ( ; ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through Mali, Nige ...
and the markets and rich resources of West Africa.
There are several small depressions in the vicinity of Cape Juby; at 55 m below sea level, the
Sebkha Tah is the lowest and largest. But it covers less than 250 km² and is 500 km north of the geographical area identified as
El Djouf (also known as the
Majabat al-Koubra) which has an average elevation of 320m.
Mackenzie never travelled in this area but had read of other sub-sea level desert basins in present-day
Tunisia
Tunisia, officially the Republic of Tunisia, is a country in the Maghreb region of North Africa. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia also shares m ...
,
Algeria
Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. It is bordered to Algeria–Tunisia border, the northeast by Tunisia; to Algeria–Libya border, the east by Libya; to Alger ...
, and
Egypt
Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...
similar to those found near Cape Juby.
These basins contain seasonally dry
salt lake
A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per liter). I ...
s, known as
chotts or
sebkhas.
François Elie Roudaire, a French geographer, and
Ferdinand de Lesseps, a diplomat influential in the creation of the
Suez Canal
The Suez Canal (; , ') is an artificial sea-level waterway in Egypt, Indo-Mediterranean, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez and dividing Africa and Asia (and by extension, the Sinai Peninsula from the rest ...
, proposed this area for the creation of an inland sea in 1878. Roudaire and de Lesseps proposed that a channel be cut from the
Gulf of Gabès
The Gulf of Gabes (or Cabès, Cabes, Gaps; ), also known as Lesser Syrtis (from ; ), contrasting with the Greater Syrtis in Libya, is a gulf on Tunisia's east coast in the Mediterranean Sea, off North Africa. The gulf roughly spans the coast from ...
in the Mediterranean to the
Chott el Fejej which would allow the sea to drain into these basins. They were not specific in the area such a sea would cover (although subsequent analyses suggested that it would be considerably smaller than Mackenzie's proposal at only in area), but argued that the new inland sea would improve the quality of weather on the European continent.
The estimated cost of the Roudaire project was $30,000,000 at the time.
While Roudaire and de Lesseps were optimistic about the weather effects that such an inland sea would produce in Europe, others were not as hopeful. Alexander William Mitchinson argued that flooding substantial areas would create disease-ridden swamps.
Others were critical of the feasibility of the project or the proposal to join the sea at El Djouf with the sea in what is now Tunisia and Algeria.
The project was ultimately rejected by the French Government and funding was withdrawn when surveys revealed that many areas were not below sea level as had been believed.
20th century
The proposal to create a Sahara Sea was revived in the early 1900s by
French professor
Edmund Etchegoyen. Around 1910, Etchegoyen proposed that a longer and deeper channel could be constructed. He argued that such a sea could be a boon for colonisation and could potentially produce an inland sea half the size of the Mediterranean.
This proposal was considered by the French government but also rejected. Critics noted that, while some parts of the Sahara were indeed below sea level, much of the Sahara was above sea level. This, they said, would produce an irregular sea of bays and coves; it would also be considerably smaller than estimates by Etchegoyen suggested.

A proposal similar to that of Roudaire and de Lesseps was raised by members of
Operation Plowshare, an American idea to use nuclear explosives in
civil engineering
Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...
projects such as the
Qattara Depression Project.
It was also suggested that nuclear explosives might be detonated to create a channel from the Mediterranean to the chotts of Tunisia.
This proposal was abandoned,
however, with the signing of various treaties prohibiting
peaceful nuclear explosions.
21st century
The project regained steam in the mid 2010s with the creation of the association Cooperation Road which in 2018 obtained the approval of the Tunisian government.
Appearances in literature
The notion of a Sahara Sea has been featured several times in literature, most notably in
Jules Verne
Jules Gabriel Verne (;''Longman Pronunciation Dictionary''. ; 8 February 1828 – 24 March 1905) was a French novelist, poet and playwright.
His collaboration with the publisher Pierre-Jules Hetzel led to the creation of the ''Voyages extraor ...
's last novel, ''
Invasion of the Sea'', which directly referred to the plan of Roudaire and de Lesseps.
The idea of a flooded Sahara also occurs in ''
The Secret People'' by
John Wyndham
John Wyndham Parkes Lucas Beynon Harris (; 10 July 1903 – 11 March 1969) was an English science fiction writer best known for his works published under the pen name John Wyndham, although he also used other combinations of his name ...
.
In the 2018 film ''
Aquaman
Aquaman is a superhero appearing in American comic books published by DC Comics. Created by Paul Norris and Mort Weisinger, the character debuted in ''More Fun Comics'' #73 (November 1941). Initially a backup feature in DC's anthology titles ...
'', the Sahara was once a sea inhabited by an Atlantean tribe.
Other desert flooding projects
Since the late 19th century there have been proposals to connect
Lake Eyre
Lake Eyre ( ), officially known as Kati Thanda–Lake Eyre, is an endorheic lake in the east-central part of the Far North (South Australia), Far North region of South Australia, some 700 km (435 mi) north of Adelaide. It is the larg ...
in the South Australian desert to the ocean via canal.
In 1905, engineers working on an irrigation canal in southern California accidentally released the waters of the
Colorado River
The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...
into a formerly dry basin, creating a large saline lake known as the
Salton Sea
The Salton Sea is a shallow, landlocked, highly salinity, saline endorheic lake in Riverside County, California, Riverside and Imperial County, California, Imperial counties in Southern California. It lies on the San Andreas Fault within the S ...
. Although the lake has shrunk considerably since its creation, it remains the largest lake in the state of California.
References
{{Levels of technological manipulation of matter
Fictional oceans and seas
Macro-engineering
Marginal seas of the Mediterranean
Proposed canals
Sahara